1. Field of the Invention
The present invention relates to a feeding apparatus for chip components, and more particularly to a feeding apparatus for aligning chip components in one row and feeding the components by utilizing a load input from a chip mounter.
2. Description of the Related Art
Conventionally, there is proposed a feeding apparatus for chip components which comprises a component accommodation chamber formed between a stationary drum and a rotary drum and suited to accommodate the chip components, a chute groove formed in the inner periphery of the component accommodation chamber, a gate port formed in the lower end of the chute groove, allowing chip components sliding down along the chute groove in a predetermined posture to pass therethrough one by one, a discharging path for aligning the chip components in one row and discharging the components, and a claw formed on the inner wall of the rotary drum, suited to energize a chip component stopping in the gate port in an abnormal posture oppositely to the discharging direction to release the clogging of the chip component (Japanese Unexamined Patent Application Publication No. 11-71019). The rotary drum is rotation-driven continuously in one direction by means of an electric motor.
The chip components aligned in one row and discharged from the discharging path is conveyed to a take-out position by means of a conveying means disposed in the end of the discharging path. There, the chip components are adsorbed one by one by a chip mounter to be taken out, and is mounted onto a printed substrate or the like. Thus, by rotating the rotary drum by utilizing a driving force for the chip mounter, a driving source for rotating the rotary drum becomes unnecessary. Advantageously, the structure can be simplified, and moreover, the rotation of the rotary drum and the absorption and taking-out of the chip components can be synchronously carried out.
In recent years, a high feeding capability is demanded for feeding apparatuses for components. The feeding time per one chip component of up to 0.1 second has been gradually realized. When a chip component is fed in such a short time, it is necessary to rotate the rotary drum at a high speed. The chip component, if it is clipped between the claw of the rotary drum and the gate port, may be broken.
Accordingly, it is an object of the present invention to provide a feeding apparatus in which for driving of a rotary member, an especial driving source is unnecessary, and breaking of a chip component can be prevented by escaping an excessive force applied when the chip component is caught in the rotary member.
To achieve the above object, according to the present invention, there is provided a feeding apparatus for a chip component having a component accommodation chamber for accommodating many chip components, an alignment path for aligning the chip components in the component accommodation chamber on one row to discharge, and a rotary member for solving clogging of a chip component in the alignment path, which comprises a feed lever operable to be reciprocated linearly or swiveled correspondingly to a load input from a chip mounter, and a conversion mechanism for converting the motion of the feed lever to the rotational movement of the rotary member and having a torque limit function of escaping the rotational force of the rotary member when the rotational resistance of the rotary member becomes higher than a predetermined value.
In this feeding apparatus, with a load input of the chip mounter, the feed lever is reciprocated linearly or swiveled. This movement is converted to the rotational movement of the rotary member through the conversion mechanism. The rotary member release clogging of a chip component in the alignment path. At this time, the chip component may be clipped between the rotary member and the component accommodation chamber, so that a large resistance to the rotation would be generated. In this case, with the torque limit function of the conversion mechanism, the rotational force of the rotary member is escaped to prevent an excessive load from being applied to the chip component. Thus, breaking of the chip component can be prevented.
Preferably, the alignment path comprises a chute groove formed in the inner periphery of the component accommodation chamber and suited to align chip components in a predetermined direction and slide the chip components downward, a gate port formed in the lower end of the chute groove and permitting chip components sliding down in a predetermined posture along the chute groove to pass therethrough, and a discharging path for aligning the chip components passed through the gate port in one row to discharge.
In this case, with the chute groove, the chip components are arranged in direction, and moreover, the postures are arranged by making the chip components pass the gate port. Thus, with the two steps of arrangement, the chip components are arranged at any time to have constant direction and postures.
Preferably, the rotary member is a claw portion provided on the inner wall of a rotary drum constituting one side wall of the component accommodation chamber, operable to be rotated along the inner periphery of the component accommodation chamber, and sited to energize a chip component stopping in the gate port in an abnormal posture oppositely to the discharging direction to release the clogging.
In this case, a part of the component accommodation chamber functions as the rotary member. Thus, the number of parts can be reduced, and the structure can be simplified.
As the conversion mechanism, different types are suggestable. For example, preferably, the conversion mechanism comprises a shaft for swivelably supporting the feed lever, a driving pulley attached to the shaft, a driven pulley attached to the rotary member, a one-way clutch provided between the shaft for the feed lever and the driving pulley or between the rotary member and the driven pulley, and a belt provided between and wound around the driving pulley and the driven pulley, whereby the belt is slid when a torque higher than a predetermined value is applied to the driving pulley or the driven pulley. Thus, the torque limit functions can be performed.
Also preferably, the conversion mechanism comprises a power transmission means provided between the feed lever and the rotary member and utilizing an eddy current damper, and a one-way clutch allowing the rotary member to rotate only in one direction. In this case, the eddy current damper causes the torque limit function. The eddy current damper may comprise a non-magnetic conductor provided on one of the member, a yoke provided on the other of the member, constituting a magnetic path, and a magnet attached to the yoke in such a manner that a flux acts on the non-magnetic conductor orthogonally. When relative movement is caused between the conductor and the yoke, an eddy current is induced in the conductor in the direction in which the magnetic flux of the eddy current is prevented from changing. The eddy current causes a resisting force between the yoke and the conductor. With the resisting force, the rotary member can be rotated following the feed lever. If a chip component is clipped between the rotary member and a member near to the rotary member while chip components are aligned, the eddy current damper escapes an excessive force applied to the rotary member, so that breaking of the chip component can be prevented. The eddy current damper has no sliding parts, and therefore, the torque limit function is not changed, e.g., by abrasion. The torque limit function can be kept for a long time period.
Moreover, the conversion mechanism may comprise a swiveling member interlocked with the feed lever and provided coaxially with the rotary member, a power transmission means provided between the swiveling member and the rotary member and utilizing an eddy current damper, and a one-way clutch allowing the rotary member to rotate only in one direction. When the power transmission mechanism utilizing the eddy current damper is provided between the feed lever and the rotary member, as described above, a loss in the driving force is large, since the former is moved linearly, and the latter is rotated. On the other hand, in the case in which the eddy current damper is provided between the swiveling member and the rotary member which are coaxially rotated, a loss in the driving force generated by the eddy current damper can be reduced, even when the feed lever is linearly moved.
Preferably, the conversion mechanism comprises a first swiveling member interconnected with the feed lever and operable to be swiveled by operation of the feed lever, a second swiveling member provided coaxially with the first swiveling member and operable to be swiveled correspondingly to the movement of the first swiveling member, a power transmission means provided between the first and second swiveling members and utilizing an eddy current damper, and a one-way clutch allowing the rotary member to rotate only in one direction. Also in this case, even when the feed lever is linearly moved, the eddy current damper effect can be effectively achieved, since the first swiveling member and the second swiveling member are coaxially swiveled. Moreover, the first and second swiveling members, and the eddy current damper mechanism can be provided at different positions from those of the feed lever and the rotary member, the flexibility of the layout is enhanced, and the height of the feeding apparatus can be decreased. When the swiveling member and the rotary member are coaxially rotated, as described above, the swiveling member is increased in size, and the motion of the feed lever is slow, affected by the inertia. On the other hand, in this conversion mechanism, the first and second swiveling members can be formed so as to have a small size, and therefore, effects of inertial can be reduced.